髓底穿通修复材料密封性的比较研究

选择３２颗新近拔除的磨牙，３号球钻由冠方进入造成髓底穿孔，分为４个实验组，分别充以氧化锌丁香油糊剂、氢氧化钙糊剂、磷酸锌水门汀及玻璃离子粘固粉，丁氧膏密封牙合面。各牙表面涂指甲油后，浸入１％中性红染液，１０天后取出，测各牙穿孔处染液渗入高度。结果显示：实验组染液渗入高度１组＜２组＜３组＜４组，提示４种材料相比，氧化锌丁香油糊剂用于底穿修复的密封性能最好。     

组织学实验课教学方法的探讨

目的　 探讨组织学实验课的教学方法 ,提高教学质量。方法　 在组织学实验课上 ,分别采用幻灯讲解、放映电视录像等方法对学生进行辅导 ;要求学生分别做绘镜下实像图、模式图、填图作业 ,在此基础上 ,组织学生进行讨论 ,并列表调查学生对上述 3种作业和 2种辅导的反映。结果　 赞成幻灯讲解辅导的人数 ( 71 % )显著地多于赞成放电视录像辅导的人数 ( 2 9% ) ,具有显著性差异 ( P<0 .0 0 1 )。 61 %的学生认为 ,在节约时间、检查发现学习的薄弱环节、增加复习面、调动学习积极性等方面 ,填图优于绘图。赞成做填图作业的人数 ( 94% )显著地多于赞成做绘图作业的人数 ( 4 % ) ,差异显著 ( P <0 .0 0 1 )。结论　 在目前的条件下 ,作为组织学实验课上的集体辅导 ,电视录像并不能完全代替幻灯讲解 ;让学生做填图作业 ,在节约时间、调动学习积极性、发现学习的薄弱环节、加深学习印象、增加复习的广度等方面明显地优于做绘图作业 ,值得在教学中推广。     

Substantial regional differences in the biomechanical behavior of molar treated with selective caries tissue removal technique: a finite element study

ObjectivesSelective caries removal (SCR) is recommended over non-selective removal for managing deep carious lesions to avoid pulp exposure and maintain pulp vitality. During SCR, residual carious dentin is left behind and sealed beneath the restoration. The biomechanical effects of such residual lesions on the restored tooth remain unclear and were assessed using finite element modeling (FEM).MethodsBased on μ-CT images of a healthy permanent human third molar, we developed five finite element models. Generic class I and II cavity restorations were modeled where residual lesions of variable sizes were either left or fully removed on occlusal and proximal surfaces. The cavities were restored with adhesive composite. All 3D-FE models were compared with a model of a healthy, non-treated molar. A vertical load of 100 N was applied onto the occlusal surface.ResultsRegardless of the lesion size, in molars with occlusal lesions higher mean stresses were predicted along the filling-lesion interface than in all other models. The smallest occlusal lesion (Ø₁ = 1 mm) resulted in the highest maximum stresses at the filling-lesion interface with large stress concentrations at the filling walls indicating failure risk. In conclusion, lesion site and extent are influencing parameters affecting the filling-lesion interactions and thus the biomechanical behavior of the tooth after SCR.SignificanceRetaining carious lesions around the pulpal floor affects the deformation and stress states in tooth-filling complexes. The higher stresses observed in molars with occlusal lesions may affect restoration stability and longevity. Suprisingly, more extended occlusal lesions may provide a more favorable tooth performance than less extended ones. In contrast, in molars with proximal lesions the residual lesion had only limited effect on the tooth’s biomechanical condition.     

Periradicular lesions in HIV-infected patients attending the faculty of dentistry: clinical findings,socio-demographics status,habits and laboratory data - seeking an association

OBJECTIVE:

The purpose of this study was to estimate the prevalence of periradicular lesions in HIV-infected Brazilian patients and to assess the correlation of several factors with the periradicular status.

METHOD:

One hundred full-mouth periapical radiographs were evaluated. A total of 2,214 teeth were evaluated for the presence of periradicular lesions, caries lesions, coronal restorations, pulp cavity exposure and endodontic treatment.

RESULTS:

The prevalence of periradicular lesions was 46%. There were no significant differences between individuals with or without periradicular lesions with respect to their socio-demographic status, habits, laboratory data and route of HIV infection. However, the presence of a periradicular lesion was statistically correlated with the number of teeth with endodontic treatment (p = 0.018), inadequate endodontic treatment (p = 0.025), images suggesting pulp cavity exposure (p = 0.002) and caries lesions (p = 0.001).

CONCLUSIONS:

The prevalence of periradicular lesions in HIV-infected individuals was 46% and was not related to HIV infection.     

Menièresche Krankheit und Akustikusneurinom

Summary It is questionable whether a hydrops endolymphaticus can develop on the basis of an acousticus-neurinoma. Histological evidence is also lacking. The fact that an acousticus-neurinoma can very rarely lead to the classical symptoms of Menière's disease has practical consequences. If a significant decrease in caloric function and an asymmetry in the inner ear ducts exist, a meato-cisternography is indicated. In the meato-cisternogramme typical filling defects are found; but also in 50% of the patients with Menière's disease, certain types of filling defects are seen. This observation suggests that perhaps other pathological processes in the inner ear duct provoke symptoms similar to those of Menière's disease. In our patient material we have indications that isolated intrameatal liquor circulation disturbances and intrameatal angioma are much more often associated with the clinical symptoms of Menière's disease than an acousticus neurinoma.

     

微创技术在乳牙牙龋中的应用

目的：探讨微创技术修复乳牙牙龋的方法及临床效果。方法：选取本院口腔科2007年6月～2009年6月收治的90例龋齿患儿为研究对象,随机分为观察组和对照组,对照组采用常规磨牙去龋治疗,观察组采用微创技术治疗（伢典凝胶去龋）,比较两组患儿的临床疗效、合作率和疼痛率。结果：观察组和对照组的成功率分别为81.3%（48/59）、84.5%（49/58）,差异无统计学意义,P〉0.05。但观察组患儿的合作率和疼痛率要显著优于对照组,P〈0.05。结论：微创治疗患儿龋齿疗效安全可靠,其疼痛小,患儿合作率高。     

Modeling powder encapsulation in dosator-based machines: II. Experimental evaluation

A theoretical model was previously derived to predict powder encapsulation in dosator-based machines. The theoretical basis of the model was discussed earlier. In this part; the model was evaluated experimentally using two powder formulations with substantially different flow behavior. Encapsulation experiments were performed using a Zanasi encapsulation machine under two sets of experimental conditions. Model predicted outcomes such as encapsulation fill weight and plug height were compared to those experimentally obtained. Results showed a high correlation between predicted and actual outcomes demonstrating the model's success in predicting the encapsulation of both formulations. The model is a potentially useful in silico analysis tool that can be used for capsule dosage form development in accordance to quality by design (QbD) principles.     

超声波洁治对提高光敏树脂楔状缺损充填效果的临床研究

目的探讨超声波洁治对提高楔状缺损的治疗效果。方法将140例患者随机分为两组,缺损面洁治组（A组）超生洁治;对照组（B组）一般清洁后以光敏树脂常规充填。结果治疗后第1年和第2年,洁治组有效率分别为87.32%和80.30%：对照组有效率分别为61.18%和50.80%。两组治疗效果有明显差异（P〈0.05）结论以超声洁治器对楔状缺损的缺损面进行洁治处理,可以提高光敏树脂的充填效果。     

平战结合注射液瓶自动冲洗吹干灌药封口机的研制

目的研制平战结合注射液瓶自动冲洗吹干灌药封口机。方法采用微电脑与光机电一体化技术将送瓶、检瓶、冲洗、吹干、灌药、封口及计数等工序组合成一条全自动的连续生产线。结果该机能成功地将上述操作工序组合成一条全自动的连续生产线,适用于生产5ml、10ml和20ml等各种规格的注射液,可取代繁琐的手工操作和设备。结论该机造型新颖小巧和功能齐全、自动化程度高,既适用于军队野战条件,也适用于军内外医院制剂室平时应用。